Month: February 2017

Post navigation

Capacify has introduced readers to some distinctly odd forms of transport over the years, from missile mail to quick-turnaround aircraft with swappable passenger pods; from seagoing trams to transporter bridges. I like to bring you the good, the bad and the ugly of the logistics world, and today is no exception as we look at Brennan’s Gyrocar: monorail, the hard way.

When you design a train to run on a single rail, you’ve got inherent instability to deal with. One solution is to hang the cars beneath the track, as seen in the venerable Wuppertal Suspension Railway, or the H-Bahn at Düsseldorf International Airport. (There are others.) If you don’t mind supporting the whole length of your track on a series of elaborate pillars, this solution is fine.

Looking for a townhouse with a view of lots of girders? Look no further than Wuppertal!

If hanging down from an overhead track doesn’t appeal, another way to achieve stability is by straddling the guideway and using additional wheels that don’t bear the weight of the vehicle, but keep it steady. The Lartigue Monorail system featured a pair of guide rails on each side for just this purpose. The top rail was supported by a line of waist-high trestles that marched across the countryside and made it just about impossible to construct any sort of level crossing, so you’ve got a fairly impractical mode of transport here.

The Lartigue Monorail, Ballybunion

Strange but true: freight cars on the Lartigue Monorail were split down the middle like panniers, and loads had to be balanced. A farmer taking a cow to market would have to balance her with two calves, then split up the calves and put one on each side for the return journey. Nothing says “technical limitations” like having to give livestock an entirely needless tour of the countryside, but the Lartigue Monorail carried passengers, freight and bemused cattle between Listowel and Ballybunion from 1888 to 1924.

With me so far? [image: Fox Broadcasting]

Modern straddling monorails are in a sense descended from the Lartigue system, using guide wheels to ensure they stay upright, with a certain amount of friction and wear-and-tear as you might expect. So far so ordinary… but there is another way.

Why not gyro-stabilise your monorail, to keep it atop a much less substantial rail? That’s what Louis Brennan (1852–1932) proposed. Not just to keep it upright, either: if you’re clever (and Brennan clearly was) you can use the gyroscopic force of precession in your favour. He patented an arrangement whereby a pair of contra-rotating gyroscopes helped his machine to balance, and to return to the vertical when subjected to a load.

When it encounters a curve, Brennan’s patented gyro mechanism causes the car to lean into the bend, just as a cyclist would. In effect, to those on board the train, the banked turn wouldn’t feel like a turn at all: their weight would keep on pressing directly down through the floor of the vehicle. That offers a considerable improvement over conventional railways, which in some cases have to feature a bend radius as large as 7km, in order to keep the passengers comfortable. Brennan used to give demonstrations in which a scale model would make its way along a tortuously twisted piece of gas pipe, as described by Cleveland Moffett, a journalist for Munsey’s Magazine:

“As she comes closer we hear the low hum of her hidden gyroscopes (they will be quite noiseless in the larger model), and are struck by the car’s remarkable width in proportion to her length. She suggests a trim little ferry-boat, and is utterly unlike any known form of railway car. Now the track curves sharply to the right; she takes the turn with the greatest ease, and leans slightly toward the curve. Now the track turns again, and she glides behind the bushes. Coming out on the other side, she enters bravely on the approach to a mono-rail suspension-bridge, a wire rope stretched over the valley that falls away between two small hills — seventy-odd feet of tight-rope-walking for the little car. Straight across she runs from side to side, — no wavering, no tipping, — and then straight back again as the assistant reverses her; then out to the middle of the rope, where they stop her, and there she stands quite still and true, while the gyroscopes hold her. This is something never yet seen in the world — a mass of dead matter, weighing as much as a man, balancing itself unaided on a wire!”

History does not record how much pocket money Brennan had to pay his children for their part in monorail demonstrations

I found that old scale model in the chaotic part of the National Railway Museum that they call the Warehouse. Somewhat neglected and missing its cab, it alerted me to the existence of this strange mode of transport.

Detail of the Brennan Gyrocar model at the National Railway Museum [image: Stephen Holland]

Brennan imagined his full-scale vehicles would cross gorges on a ‘bridge’ consisting of a single steel cable, and ascend gradients of up to one in five. The guideway upon which it ran was simple – just a round ‘pipe’ shape on sleepers, far cheaper than the elaborate Wuppertal or Lartigue types. This will have been what attracted the British Army Council, the Durbar of Kashmir and the India Office to the idea, and they all reached for their chequebooks.

Brennan’s Gyrocar at the Japan-British Exhibition of 1910

A full-size prototype railcar (12.2m by 3m) was completed and running by October 1909, and it was first shown to the public at the Japan-British Exhibition of 1910. The monorail car took up to fifty passengers at a time on a short ride. Among those who tried it was Winston Churchill, MP, who would have been around 36 at the time. The gyro monorail had proved itself a workable technology… but there the story ends: no commercial system based on the technology would appear in the years that followed. Still, Brennan’s gyrocar had been demonstrated something like 63 years before the Advanced Passenger Train prototype rolled out – another tilting train concept meant to reconcile the conflicting requirements of curves, speed, and passengers’ comfort. Despite running on conventional tracks, the newer tilting train was plagued by technical troubles, and was withdrawn from service (although the Italians later managed to make the concept work, and called it the Pendolino).

For the gyro monorail, some problems clearly remain. For one thing, you can’t detect the presence of a vehicle on the track (for safety and signalling purposes) by the usual means of having the train itself complete a circuit, so an alternative way to ensure the line is clear would have to be found. (Hardly an insurmountable task nowadays.)

A bigger problem, of course, is that when your gyroscopes stop spinning, the gyrocar ceases to balance. This might seem to be a little bit worrying if your Brennan gyro train is on an elevated section, or perhaps crossing one of Brennan’s single-wire minimalist suspension bridges over a gorge. Actually, it’s not necessarily all that bad. Travelling on a straight section (such as that bridge) a single working gyro would be enough to keep a car upright: it’s only on curves where you need the contra-rotating pair in order to balance correctly. Also, gyroscopes that lose power take quite a while to spin down to nothing, so a gyrotrain driver with instrumentation ought to be able to take corrective action in good time.

The most significant limitation of the gyrocar technology isn’t apparent from the demonstrator on which our future Prime Minister rode. All the gyrocars ever demonstrated have been exactly that: cars, and not trains. Brennan’s paired gyroscope arrangement has to feature in every section of the train, with no such thing as a passive ‘trailer’ unit, since even if it doesn’t provide traction the coach or wagon must still feature powered gyros, or it won’t be able to balance. The rolling stock for such a transport network would cost a fortune.